1. Field of Invention
The present invention relates to an image forming apparatus using an electrophotographic system, such as a copying machine, a printer, a facsimile, or a combination machine of the above machines, and more specifically to an image forming apparatus in which a special toner image can be obtained in addition to a normal toner image.
2. Description of Related Art
Conventionally, an image forming apparatus such as a copying machine or a printer that utilizes the electrophotographic system or the electrostatic transfer system is widely known. In such an image forming apparatus, a black-and-white image, a full-color image formed with toners of yellow, cyan, and magenta, and the like are usually formed on a paper and outputted. In addition, unlike the technique for obtaining these (flat) images, there has been proposed a technique for obtaining a three-dimensional image using a special toner (foaming toner). For example, the applicant has already proposed xe2x80x9cImage forming toner, preparation method thereof, three-dimensional image forming method and image forming apparatusxe2x80x9d and xe2x80x9cImage forming apparatusxe2x80x9d in JP 2000-131875 A and JP 2001-194846 A, respectively.
Incidentally, the special toner has preferable fixing conditions that are different from those of the normal toner in terms of characteristics. For example, in order to form a satisfactory three-dimensional image, in general, it is necessary to give a foamable toner a heat quantity larger than that for the normal toner.
The present invention has been made in view of the above circumstances and provides an image forming apparatus capable of forming an image with the normal toner and forming an image with the special toner, which makes it possible to perform appropriate fixing of a toner to be used according to characteristics of the toner.
According to the present invention, there is provided an image forming apparatus including: an image bearing member; a first developing unit for forming an image consisting of one type or plural types of first developer on the image bearing member; a second developing unit for forming an image consisting of one type or plural types of second developer different from the first developer on the image bearing member; a transfer section for transferring the image formed on the image bearing member to a recording medium; a fixing apparatus for fixing the image on the recording medium under predetermined fixing conditions and conveying the same; a developing unit judging section for judging a type of a developing unit used by the image forming apparatus; and a control unit for controlling the fixing conditions based on a judgment result of the developing unit judging section.
Further, according to the present invention, there is provided an image forming apparatus including: an image bearing member; a first developing unit for forming an image consisting of one type or plural types of first developer on the image bearing member, a transfer section for transferring the image formed on the image bearing member to a recording medium; a fixing apparatus for fixing the image on the recording medium under predetermined fixing conditions and conveying the same, the image forming apparatus is capable of having mounted thereto a second developing unit for forming an image consisting of one type or plural types of second developer different from the first developer on the image bearing member; a developing unit judging section for judging a type of a developing unit used by the image forming apparatus; and a control unit for controlling the fixing conditions based on a judgment result of the developing unit judging section.
As described above, the image forming apparatus may be provided with both the first developing unit and the second developing unit from an initial state of development or may be provided with only the first developing unit in the initial state and mounted with the second developing unit later (additionally or alternatively).
Further, the image forming apparatus may comprise a user interface section in which an instruction from a user is inputted, wherein the developing unit judging section judges a type of a developing unit used by the image forming apparatus based on an instruction from the user interface section. Alternatively, the image forming may further comprise an image processing section in which an image forming command is inputted, wherein the developing unit judging section judges a type of a developing unit used by the image forming apparatus based on a result of analysis of the image forming instruction by the image processing section.
The control unit can control the fixing conditions such that first fixing conditions in using only the first developing unit and second fixing conditions in using only the second developing unit are different from each other. In addition, in the case where both the first developing unit and the second developing unit are used, the control unit can control the fixing conditions such that intermediate fixing conditions between the first fixing conditions and the second fixing conditions are realized. Moreover, the control unit can also determine the intermediate fixing conditions according to a frequency of using the first developing unit and the second developing unit. That is, the control unit can determine the intermediate fixing conditions such that the intermediate fixing conditions become closer to the first fixing conditions in the case where the first developing unit is used more frequently or closer to the second fixing conditions in the case where the second developing unit is used more frequently.
In addition, the first developer and the second developer can be distinguished from each other in that the first developer does not contain a foaming agent and the second developer contains a foaming agent, the first developer contains a colorant of a nonmetallic color and the second developer contains a colorant of a metallic color, the first developer contains a colorant of a chromatic color and the second developer contains a colorant of an achromatic color, or the first developer contains a specific colorant and the second developer contains a colorant different from the specific colorant.
Examples of the first developer include a developer (of one type) containing a colorant of black, developers of three types containing colorants of yellow, magenta, and cyan, respectively, and developers of four types containing a colorant of black in addition to these developers of three types. In addition, as examples of the second developer, there are a colorless developer (of one type) containing a foaming agent and not containing a colorant, a developer (of one type) containing a foaming agent and a colorant, a developer (of one type) not containing a foaming agent and containing a colorant of a metallic color, and developers of plural types that are arbitrary combinations of the above-mentioned developers. Note that the foaming agent and the colorant may be internally added or externally added to a developer.
Here, when the first developer does not contain a foaming agent and the second developer contains a foaming agent, fixing conditions can be controlled as described below.
First, the fixing section is provided with a pair of fixing rotators that come into press-contact with each other and rotate at a predetermining fixing rate, and a second fixing rate that is the second fixing condition is controlled to be lower than a first fixing rate that is the first fixing condition.
Second, the fixing section is provided with a pair of fixing rotators that come into press-contact with each other and rotate and a heating source that heats at least one of the pair of fixing rotators to a predetermined fixing temperature, and a second fixing temperature that is the second fixing condition is controlled to be higher than a first fixing temperature that is the first fixing condition.
In relation to the image forming apparatus described above, the fixing section is provided with a pair of toner side and non-toner side fixing rotators that come into press-contact with each other and rotate and a heating source that heats the non-toner side fixing rotator to a predetermined fixing temperature, and a second fixing temperature that is the second fixing condition is controlled to be higher than a first fixing temperature that is the first fixing condition.
Third, the fixing section is provided with a pair of fixing rotators that come into press-contact with each other and rotate, a heating source that heats one of the pair of fixing rotators, and a latch section that brings the pair of fixing rotators into press-contact with each other from a separated state at predetermined latch timing, and second latch timing that is the second fixing condition is controlled to be earlier than first latch timing that is the first fixing condition.
Fourth, the fixing section is provided with a pair of fixing rotators that come into press-contact with each other and rotate and a peeling member that is provided in a predetermined position on a downstream side of the press-contact portion and peels a recording medium adhering to the fixing rotators, and a second position that is the second fixing condition is controlled to be apart from the press-contact portion by a larger distance than a first position that is the first fixing condition.
Fifth, the fixing section is provided with a pair of fixing rotators that come into press-contact with each other and rotate and a conveyor member that conveys a recording medium after passing through the press-contact portion at a predetermined conveying speed, and a second conveying speed after fixing that is the second fixing condition is controlled to be lower than a first conveying speed after fixing that is the first fixing condition.
Note that the fixing rotator may have a roll shape or an endless belt shape. In addition, the pair of fixing rotators may be a pair of rolls, a pair of endless belts, or a combination of a roll and an endless belt.
In addition, the second developing unit may be mountable in place of the entirety or a part of the first developing unit (alternatively) or may be mountable in addition to the first developing unit (additionally). Further, the developing unit may be mounted on an image forming apparatus one by one or may be mounted on the image forming apparatus in a plural form collectively. Moreover, the developing unit may be mounted on the image forming apparatus independently or may be mounted on the image forming apparatus as an image forming unit including an image bearing member in addition to the developing unit.
In addition, in order to judge a type of a mounted developing unit, the developing unit may have a special shape corresponding to a developer therefor and have a developing unit judging section for judging a type of a mounted developing unit based on the special shape. Alternatively, the developing unit may have a developing unit judging section that is provided with a nonvolatile memory and, at the same time, stores developer information indicating a developer therefor in the nonvolatile memory and judges a type of a mounted developing unit based on the developer information read from the nonvolatile memory. Moreover, in the case where the developing unit is mounted on the image forming apparatus as an image forming unit including an image bearing member in addition to the developing unit, the image forming unit may have a special shape corresponding to a developer therefor or may be provided with a nonvolatile memory.
In addition, the transfer unit may include only a final transfer section and transfer an image on the image bearing member to a recording medium directly. Alternatively, the transfer unit may be provided with an intermediate transfer member and an intermediate transfer section in addition to the final transfer section, transfer an image on the image bearing member to the intermediate transfer member once by the intermediate transfer section, and further transfer the image on the intermediate transfer member to a recording medium by the final transfer section.
Further, the present invention can be applied to any image forming apparatus of the electrophotographic system. Turning to a relationship between a developing unit and an image bearing member (photosensitive member, latent image bearing member), there are an image forming apparatus in which each developing unit and image bearing member has a one to one relationship and an image forming apparatus in which each developing unit and image bearing member has an N (N is a natural number) to one relationship. As examples of the former image forming apparatus, there are a monochrome image forming apparatus, a full-color image forming apparatus of the tandem system using an intermediate transfer member, from an upstream side to a downstream side of which image forming units corresponding to each color are arranged, and the like. As examples of the latter image forming apparatus, there are image forming apparatus using a developing apparatus of the rotary system, a full-color image forming apparatus in which developing units corresponding to each color are arranged from an upstream side to a downstream side of an image bearing member, and the like.
According to the present invention, there is provided an image forming apparatus capable of forming an image with a normal toner and forming an image with a special toner, which makes it possible to perform appropriate fixing according to characteristics of a toner to be used.